I have a solar panel, mains batterycharger and alternator connected to a battery mate 1603 battery isolator, which is connected to three separate batteries (house, cranking, windlass). The solar panel and charger each have a switch between them and the isolator but the alternator is connected directly.

I hardly ever use the battery charger, as the solar panel generates enough charge to keep the batteries topped up between use.

On the weekend I tried to use the charger. When I turned it on the battery alarm on the engine key switch came on. The mains charger seemed to be working ok, as the monitor indicated flow to the batterys. Also when I ran the engine the alternator similarly seemed to be generating charge.

The alarm comes on when I turn the charger on without the engine running. The switch for the charger is attached to the engine key, so it's not possible to the alternator and charger at the same time.

The alarm also comes on, as normal, when the engine start key is turn on prior to the engine firing up. It stops, as normal, when the engine/alternator starts running.

When the issue arose I didn't leave the charger on very long so the battery voltage didn't change much. It was around 13v. Similarly I didn't run the engine for long enough to change the voltage, just enough to see that it was charging the battery.

On the outing the previous day, I did run the engine harder than I had previously and wonder if the charge generated fried something allowing current to flow back to the alternator from the battery isolator. Would this cause the alarm to go on?

Try disconnecting the alternator from the 1603 (engine off of course) and see if that gets rid of the alarm.

I'm not sure how you have the charger connected through your key switch but it doesn't seem right to me. The charger, IMO, should be connected to a dedicated switch. I suppose the key switch just activates a relay but I still think it should be on its own dedicated switch. What charger do you have and does it have any error code display or error lights on it?

why are you running a battery charger and solar though an isolator?...

get a 3 bank charger. get rid of the stupid engine switch control. turn it on and off from the ac breaker. there is no reason to not have both on at the same time.

run solar straight to house battery. use isolator for alternator only.

the whole setup just sounds weird.

if your battery light is coming on when the charger is turning on then somehow the charger is powering up your ign circuit. probably something to do with that silly key switch. probably some strange relay setup. never seen anything like that before.

HI. I think I am dozing a bit reading you messages. Long day. You have to turn off or disconnect all the ways to charge your batteries except for one. Only one kind of charger should ever be connected to charge at any given time to prevent damage.

Quote:

Originally Posted by stevesailing

I have a solar panel, mains battery charger and alternator connected to a battery mate 1603 battery isolator, which is connected to three separate batteries (house, cranking, windlass). The solar panel and charger each have a switch between them and the isolator but the alternator is connected directly.

I hardly ever use the battery charger, as the solar panel generates enough charge to keep the batteries topped up between use.

On the weekend I tried to use the charger. When I turned it on the battery alarm on the engine key switch came on. The mains charger seemed to be working ok, as the monitor indicated flow to the batterys. Also when I ran the engine the alternator similarly seemed to be generating charge.

DeepFrz - thanks, I'll try that- that way I'll know if the current is passing back to the alarm from the isolator/alternator or some other route

smac999 the battery charger isn't connected to the engine key switch, sorry if I wasn't clear, the switch for the charger is operated using a plastic key which is physically attached to the engine key, so they can't both be on at the same time.

DeepFrz - thanks, I'll try that- that way I'll know if the current is passing back to the alarm from the isolator/alternator or some other route

smac999 the battery charger isn't connected to the engine key switch, sorry if I wasn't clear, the switch for the charger is operated using a plastic key which is physically attached to the engine key, so they can't both be on at the same time.

OK. What about your solar panel/s? Are they on until you disconnect them or turn off?

I have all three ways to charge all 7 of my batteries. But, I have to connect them manually and disconnect them as I change ways to charge them. Mine is not automatic at either of the 3 ways to charge. I plug in I wire it on shore power charger. I unplug I connect the solar, I motor it goes on the motors generator but only the batteries I choose will be connected to motor in parallel. That way there is nothing that can break and mess up my power systems on a trip. It can be a pain in the booty at times but it works great.

When you turn on the battery charger the engine alarm goes off. If I understand correctly this is the alarm connected to the ignition and senders on the engine. Most engines will have several senders that will sound the alarm; typically oil pressure, water temp, low alternator voltage.

If the alarm is going off when the battery charger is switched on then I would guess that it is somehow sending power to the engine and ignition switch which is powering the accessory circuit which includes the alarm.

Is the engine ignition switch all the way in the off position? When you turn on the battery charger do the engine gauges activate, that is do the needles on the gauges jump? from the off position?

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I have all three ways to charge all 7 of my batteries. But, I have to connect them manually and disconnect them as I change ways to charge them. Mine is not automatic at either of the 3 ways to charge. I plug in I wire it on shore power charger. I unplug I connect the solar, I motor it goes on the motors generator but only the batteries I choose will be connected to motor in parallel. That way there is nothing that can break and mess up my power systems on a trip. It can be a pain in the booty at times but it works great.

Disconnect the alligator clamps. Even my spot light can send voltage through the panel.